A seat lifter structure which can obtain a rotation of a sector with stable torques is provided. It is equipped with a sector (7) supported to be rotatable by a support member (21), arranged to be facing with a side frame (2) by being pinched and fixed by a pair of expanded portions (6a, 6b) of a tubular shaft member (6) that is supported to be rotatable by the side frame (2), and rotating along the side frame (2) at a time of raising or lowering the side frame (2); a ring shaped spacer (13) having a first ring shaped abutting surface (13da) facing with the sector (7) and having a first outer diameter (13d2), and a second ring shaped abutting surface (13ca) facing with the side frame (2) and having a second outer diameter (13c2) different from the first outer diameter (13d2), which is installed between the sector (7) and the side frame (2) with an axial line (CL6) as a center; and a biasing member (12) that biases and abuts the sector (7) to the first abutting surface (13da) and biases and abuts the side frame (2) to the second abutting surface (13ca) by biasing the sector (7) and the side frame (2) to approach.

A brake-side clutch part to transmit a rotational torque input from a lever-side clutch part to an output side, and interrupt a rotational torque reversely input from the output side includes an inner ring, an outer ring including a recess/protrusion part, an output shaft, an engaging element including a recess/protrusion part capable of meshing with the recess/protrusion part, and a control mechanism to engage the engaging element with the outer ring through meshing between the recess/protrusion part and the recess/protrusion part when the rotational torque is interrupted, and disengage the engaging element from the outer ring through release of the meshing when the rotational torque is transmitted. The control mechanism includes a support part, which is provided between the engaging element and the inner ring, and is configured to maintain an engagement state between the engaging element and the outer ring when the rotational torque is interrupted.

A clutch unit includes a lever-side clutch part to control transmission and interruption of rotational torque input through lever operation, and a brake-side clutch part to transmit the rotational torque from the lever-side clutch part to an output side, and interrupt rotational torque reversely input from the output side. The brake-side clutch part includes a cover constrained in rotation, an output shaft to output the rotation, an inner ring to receive the rotational torque input from the lever-side clutch part, and a cylindrical roller to control interruption of the rotational torque from the output shaft and transmission of the rotational torque from the inner ring through engagement and disengagement between an outer ring and the output shaft. The inner ring includes a slide gear which meshes with the cover during interruption of the rotational torque and is released from the meshing state during transmission of the rotational torque.

A clutch unit includes a lever-side clutch part to control transmission and interruption of rotational torque input through a lever operation and a brake-side clutch part to transmit the rotational torque from the lever-side clutch part to the output side and interrupt rotational torque reversely input from the output side. The brake-side clutch part includes an outer ring constrained in rotation, an output shaft to output the rotation, cylindrical rollers to control interruption of the rotational torque reversely input from the output shaft and transmission of the rotational torque input from the lever-side clutch part through engagement and disengagement between the outer ring and the output shaft, a friction ring to apply a rotational resistance to the output shaft, and a variable part to change the rotational resistance applied to the output shaft between the transmission and the interruption of the rotational torque.

A seat lifter includes: a connecting member that connects a base member and a seat frame that form a seat and swings in response to external rotating force to raise or lower the seat frame; a first gear provided in the connecting member; a second gear that is provided such that an axial direction thereof is parallel to an axial direction of the first gear and meshes with the first gear; and an operating lever that applies rotating force to the second gear. The teeth of at least one of the first and second gears have such a shape that a tooth thickness of the teeth gradually decreases from one end toward the other end in the axial direction, and the first and second gears mesh with each other by approaching each other in the axial direction.

Disclosed is a pumping device for a seat of a vehicle, the device including: a cam mechanism rotating along with a lever; a clutch mechanism receiving power from the cam mechanism; a housing accommodating the cam mechanism and the clutch mechanism therein; a brake mechanism accommodated in the housing to receive power from the clutch mechanism, and configured such that boss portions protrude along an outer circumferential surface thereof, outer end sides of the boss portions face an inner circumferential surface of the housing, and a pressing portion protruding from the clutch mechanism is disposed between a boss portion and a neighboring boss portion; and a brake roller provided at opposite sides of each of the boss portions of the brake mechanism to be disposed between the boss portion and the pressing portion.

Disclosed is a seat pumping device for a vehicle, the seat pumping device including: a clutch drum turned by receiving torque of a lever and having a plurality of compressing protrusions radially formed along an edge thereof to be spaced apart from each other; a brake drum coupled to the clutch drum and having a circular vertical flange protruding toward the clutch drum, the vertical flange having a plurality of supporting protrusions protruding laterally of the vertical flange to be arranged between the compressing protrusions; and a securing portion provided between the vertical flange and the clutch drum which face each other, the securing portion guiding a relative turning of the clutch drum and the brake drum while blocking a relative translation of the clutch drum and the brake drum.

Disclosed is a seat pumping device for a vehicle. The seat pumping device includes: a housing having a through hole formed therein; a clutch cam positioned on an inside of the housing and coupled such that a coupling protrusion protruding outwardly of the housing through the through hole is turnable relative to the housing; a lever bracket positioned on an outside of an upper surface of the housing so as to face the clutch cam with the housing interposed therebetween, the lever bracket being coupled to the coupling protrusion of the clutch cam to be turned integrally with the clutch cam; and a supporting portion protruding from one of the upper surface of the housing and a lower surface of the lever bracket toward a remaining one, the upper surface of the housing and the lower surface of the lever bracket facing each other, the supporting portion supporting the lever bracket and the housing so as to be spaced apart from each other at a regular interval.

A fluttering prevention apparatus for a lever of a pumping device includes: a lever bracket including a first side coupled with a lever, a center portion formed with a hollow hole, and a second side formed with insertion holes; a clutch cam including a first side provided with protruding portions inserted into the insertion holes of the lever bracket; a clutch drum having a first side formed with a seat groove to receive the clutch cam is seated therein; and a spindle coupled to the hollow hole of the lever bracket through center portions of the clutch drum, the clutch cam, and the housing, thereby inhibiting the lever bracket form fluttering with respect to the clutch drum.

A clutch unit includes a lever-side clutch portion for controlling transmission and interruption of rotational torque to an output side through lever operation, and a brake-side clutch portion for transmitting torque input from the lever-side clutch portion to the output side and for interrupting torque reversely input from the output side. The lever-side clutch portion has an outer centering spring provided between a lever-side outer ring to be rotated through the lever operation and a cover restricted in rotation, for accumulating an elastic force obtained by torque input from the lever-side outer ring and for restoring the lever-side outer ring to a neutral state with the accumulated elastic force through releasing of the torque input from the lever-side outer ring.